A042151 Denominators of continued fraction convergents to sqrt(600).

1, 2, 97, 196, 9505, 19206, 931393, 1881992, 91267009, 184416010, 8943235489, 18070886988, 876345810913, 1770762508814, 85872946233985, 173516654976784, 8414672385119617, 17002861425216018, 824552020795488481, 1666106903016192980, 80797683365572751521

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0,98,0,-1).

Formula

G.f.: -(x^2-2*x-1) / ((x^2-10*x+1)*(x^2+10*x+1)). - Colin Barker, Dec 02 2013

a(n) = 98*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Jan 15 2014

Mathematica

Denominator[Convergents[Sqrt[600], 30]] (* Vincenzo Librandi, Jan 15 2014 *)
LinearRecurrence[{0, 98, 0, -1}, {1, 2, 97, 196}, 30] (* Harvey P. Dale, Jul 04 2022 *)

Prog

(Magma) I:=[1, 2, 97, 196]; [n le 4 select I[n] else 98*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jan 15 2014

Crossrefs

Cf. A042150, A040575.

Sequence in context: A139884 A297423 A189313 * A233192 A065592 A233767

Adjacent sequences: A042148 A042149 A042150 * A042152 A042153 A042154

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Colin Barker, Dec 02 2013

Status

approved